Calculate the heat needed to change a material’s temperature.
Water has an unusually high specific heat of 4,186 J/kg·K, which is why heating it takes so much energy. Dividing the heat by available power gives the time required. Heating a bathtub of water requires several kilowatt-hours, which is why hot water is typically the largest or second-largest energy use in a home.
Specific Heat
Q = m c ΔT
Q = m c ΔT Water has an unusually high specific heat of 4,186 J/kg·K, which is why heating it takes so much energy. Dividing the heat by available power gives the time required.
Heating a bathtub of water requires several kilowatt-hours, which is why hot water is typically the largest or second-largest energy use in a home.
This calculator takes 4 inputs: Mass, Specific heat capacity, Temperature change, Available heating power. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.